ITV News has learned the type of cladding that covered the exterior of the Grenfell Tower has also been used on a nearby estate in North London.
Harley Facades Ltd has confirmed it installed aluminium composite material (ACM) panels made from Reynobond at the Chalcots Estate in Camden and that the panels have a combustible polyethylene core.
At the weekend the chancellor, Philip Hammond, said this type of cladding is banned from use in high rise developments.
The Chalcots Estate comprises four 22-storey tower-blocks and one 18-storey tower block. The blocks were erected in the late 1960s and re-clad in 2006 as part of a £66 million refurbishment.
The work was carried out by the same group of companies that were used on the refurbishment at Grenfell Tower. The main contractor was Rydon. Rydon subcontracted the design and installation of the external cladding to Harley Facades. Omnis supplied Harley with the cladding panels.
In a statement Ray Bailey, the MD of Harley, said: "These works were as described in the contractual specification and approved in the usual process for construction and building control by the London Borough of Camden."
He added: "There is no evidence to suggest that this product and cladding system installed in Camden is unsafe."
The speed at which the fire spread at Grenfell Tower has led to speculation the polyethylene cladding may have been a contributing factor.
A fire expert we spoke to told us that polyethylene-core cladding "does not conform with the government's guidance that supports the building regulations" and that Camden would have to remove it.
"A polyethylene core as contained in the standard Reynobond product does not have 'limited combustibility'," the fire expert told ITV News.
"It is flammable, it is combustible. Polyethylene products cannot be of limited combustibility. Reynobond has alternative products which would have been suitable."
We asked Camden Council whether it intends to remove the cladding panels at the Chalcots Estate and, if so, what steps it intended to take in the interim to mitigate risk for residents.
Camden does not deny polyethylene-core cladding has been installed at the Chalcots Estate but was unable to confirm that it approved the Reynobond material for use in the project. The council argues the exterior cladding "system" is different to Grenfell in important respects.
In a statement Camden Council said: "The insulation used (behind the cladding panels) is made of rock wool material, which prevents fire spreading.
"We also have fire resistent sealant between floors, which would stop a flat fire from spreading - as proved when a fire was contained at a flat in Taplow block in 2012."
Camden has sent a sample of the cladding away for testing. On Sunday, the government ordered councils across the UK to check whether tower blocks in their areas have been clad using similar materials to those at the Grenfell Tower.
Local Authorities and Housing Associations that own properties which are more than 18 metres tall and have aluminium composite material (ACM) cladding must supply samples to laboratories specified by the Department for Communities and Local Government for scientific testing to establish if they are suitably fire-resistant.
So far we know that three councils - Camden, Barnet and Kensington and Chelsea - have high rise developments with exterior, polyethylene-core cladding.
Meanwhile another fire expert has told ITV News some private sector developments are also likely to be found equipped with cladding that is combustible. "This problem is not something that is unique to social housing," he said.